SYNTHESES AND CHARACTERISATION OF DIUREA MOLECULAR TWEESORS FOR THE RECOGNITION OF ANION

Two novel urea anion receptors (11) and (12) were synthesized from building block 3,3 ’ methylene diamine and was characterized via the techniques of 1H NMR, 13 C NMR, DEPT- 135 1H-1H COSY, HMQC and HMBC spectroscopy. The 1H NMR profile of both compounds reveals diagnostic peaks. For compound (11), the urea NH protons resonate as two singlets downfield at 8.706 ppm and 8.635 ppm, whereas for compound (12) these two urea –NHCONH protons resonate together at 8.614 ppm. There seem to be no rotation of the structure on the NMR time scale as the bridged CH2 protons resonate as a singlet. The integration patter